Internal combustion engines and methods of manufacturing such engines



Sept. 23, 1958 L. J. FAGEOL 2,852,837

INTERNAL coNBusTxoN ENGINES AND METHODS OF' MANUFACTURING SUCH ENGINES Filed Dec. A?, 1956 Egg@ ATTORNEYS United States Patent C INTERNAL CMBUSTIN ENGINES AND METH- DS F MANUFACTURING SUCH ENGINES Louis J.. Fageol, Kent, Ohio, assigner to Twin Coach Company, Kent, Ohio, a corporation of Ohio Application December 4, 1956, Serial No. 626,228

2 Claims. (Cl. 29-156.4)

This invention relates to improvements in internal combustion engines and components thereof and to novel methodsfor manufacturing and assembling internal combustion engines.

The need has long existed in many military and commercial applications for engines of standard design ernploying interchangeable components for installations in vehicles having widely differing power requirements. It has long been recognized particularly in connection with military vehicles that the use of a specic engine for each class of vehicles increases the original vehicle develop ment cost and increases the cost and difficulty of servicing and maintaining the vehicles in the field.

In accordance with the present invention a basic engine adapted for use with vehicles of a given size is combined with a substantially identical engine in a novel manner to produce an engine which has at least twice the power of the original engine and is thus suited for installation in larger vehicles. The invention thus provides two engines which are substantially different ratings and which utilize the same basic major components including cylinder blocks, crankshafts, pistons, camshafts and valves. In view of the interchangeability of these major components, the costs of manufacturing and servicing the two engines are substantially below the cost of manufacturing twoentirely different engines in accordance with prior practice.

For purposes of illustration, the invention will be disclosed as applied to an eight-cylinder engine of the socalled flat or pancake type in which one bank of cylinders is directly opposed to and in-line with the other bank of cylinders. Preferably the engine is assembled from components of four-cylinder in-line engines of conventional construction. However, it is to be understood that the invention is of broader application and may be successfully utilized in connection with other engines.

The construction of the connecting rod and the crankshaft is such that the cylinders of one bank are coaxial with the respective cylinders of the opposite bank. The eltective bearing area for each cylinder is the same in the eight-cylinder engine as in the four-cylinder engine. Accordingly, despite the fact that the original crankshaft usedin the four-cylinder engine transmits the power developed by eight cylinders in the converted engine the original bearing loads at the connecting rods and the crankshaft are not increased.

It is also a feature of the present invention that one cylinder in one bank is tired simultaneously with a cylinder of the opposite bank. Thus the power impulses are substantially completely balanced. Also since the pistons in the opposite banks are always reciprocating oppositely oppositely and the crankshaft is fully balanced, the engine is unusually smooth, quiet and efficient in operation.

Essentially the eight-cylinder engine of the present invention provides the same torque as a four-cylinder engine of equal displacement (which is substantially greater than the; torque produced by a conventional eight-cylinder Patented Sept. 23, 1958 ICC engine) but with much smoother and better balanced operation than the equivalent four-cylinder engine.

The high torque characteristics of the eight-cylinder engine also permit the use of a ily-wheel of the same size and Vweight as that used in the original four-cylinder engine thus permitting rapid acceleration and a flexibility of operation not previously associated with comparable prior engines.

It is a particular feature of the present invention that the eight-cylinder engine employs the same crankshaft as the original four-cylinder engine. Accordingly, a standard crankshaft serves for both engines and the length of the eight-cylinder engineis the same as the length of the four-cylinder engine. This unique advantage and other advantages of the present invention are made possible in large measure by a connecting rod of novel construction which thus also forms an important feature of the present invention.

With the foregoing considerations in mind it is an important object of the present invention to provide irnproved internal combustion engines and improved methods of manufacturing such engines.

It is also an object of the present invention to provide novel methods of combining at least two engines of a given displacement to provide a single larger engine having a displacement equal to the combined displacement of the original engines and having a horsepower greater than the sum of the horsepower produced by the original engines individually.

It is a more specic object of the invention to provide novel methods for converting a pair of four-cylinder engines into an eight-cylinder engine of the llat or pancake type having an overall length no greater than the length of the original four-cylinder engine.

It is also an important object of the present invention to provide improved novel connecting rod assemblies which permit the displacement of a pair of opposed cylinders directly in` line with each other and the connection of each of the opposed pistons to a crank pin journal having a width no greater than that used in connection with a single piston.

Additional objects and advantages will become apparent as the description proceeds in connection with the accompanying drawings in which:

Figure l is an end elevation with parts broken away of a conventional four-cylinder in-line internal combustion engine;

Figure 2 is a top plan View of the novel eight-cylinder pancake engine of the present invention;

Figure 3 is an enlarged fragmentary top plan view of the engine of Figure 2 with parts broken away; and

`Figure 4 is a fragmentary vertical section taken along line 4-4 of Figure 3.

As stated above certain of the basic concepts of the present invention are applicable to a variety of engines. In practice the invention has been successfully applied to engines of the type shown in the drawings which'are water cooled internal combustion engines of the type generally employed for automotive use. The particular engine shown in Figure l is a four-cylinder in line overhead cam engine and includes a cylinder block 20 having an integral cylinder` head 22 and a cani cover plate 24. The crankcase is of the split type and comprises the upper half 26 and the lower half of oil pan 28, the parts 26 and 28 being secured together by the usual bolts 3i) substantially at the center line of the crank shaft 32 which is supported by main bearings 33 rigidly mounted on the the latter being held in place by nuts 43.

the opposite side of which carries intake 'and exhaust manifolds 45 and 46, respectively. Since the engine of Figure 1 is in all respects conventional it is not believe that further jdetailed description is required'.

One importantaspect of the present invention involves the conversion of Vtwo engines of the type shown in Figure 1 into a single at eight oppo'sedeng'ine as shown in Figure 2. It is a feature of the invention that the conversion may be effected simply and in a manner tofperrriit the utilization of'a maximum number of the basic components of the original enginea In-Figure2 the original engine designated A appears at the left 'side ofthe figure and the `duplicate original enginefdesignat'ed B appears at the right side of the figure. `Before installation the cylinder block 20h is reversed end for end to dispose the number one cylinder 'of engine B opposite number four cylinder of engine A to thereby dispose the intake and exhaust manifolds of thetwo'blocks at the same side ofl the engine of Figure 2. Because of this reversal the tower shaft housing 47 of block 2Gb is relocated. Otherwise, the two cylinder blocks 20a and 2Gb and all of the mechanisms associated therewith are identical. It will be noted that the original crankcase half 26 is vretained in the'engine of Figure 2. In` the second engine the entire crankcase pan is removed and the cylinder block`20b is bolted directly to a crank case adapter section 48 which thus serves'as the added crankcase half for engine `B and the added crankcase half for engine A.

It is also an important feature that the original crankshaft 32 of engine A is retained inthe'co'nverted engine of Figure 2 with the result that the engine of Figure 2 is the same length as the engine of Figure 1 and the` pistons of the two engines are directly in line. In both engines the main bearings 33 support the crankshaft. This unique construction is made possible in large measureby a novel piston rod construction to which detaile'd reference will now be made. It will be noted that the connecting rods 38 of engine A are lretained in the ,final engine. However, the connecting rod caps .42 used in the original engine are replaced by caps 49. -The caps 49 are provided with a pair of spaced ears 50 and 52, the ears having aligned bores 54 and 56, respectively, formed about a center disposed in a plane containing 4the center Aof the crank pin 57 and the center of the wrist pin 36. Press fitted into the bores 54 and 56 is-a pin 58 on which one end of a modified connecting rod 60 is mounted. The pin 58 is preferably interchangeable with the original wrist pins 36a and 36h, the latter supporting the outer end of the modified connecting rod 60 in the usual manner.

It will be noted that because of the displacement of the axis of pin 58 from the center of the crank pin 57 the angular movement of the piston rod 60 during a single revolution of the crankshaft is somewhat greater than the angular movement of the connecting rod 38. To reduce this angular differential the length of the connecting rod 60 is such that the wrist pin 36b` is somewhat farther from thecenter of the crank pin 57 than the wrist pin 36. In a specific example, the distance between the center of crankpin 57 and the center of wrist pin 36a is equal to the distance between the center of pin 58 and the center of wrist pin 36b. In this example, the angular movement of the connecting rod 38 is 5 degrees less than the angular movement of the connecting rod 60. It is for this reason that the depth of the crankcase adapter section 46 is somewhat greater than that ofthe original upper crankcase section 26. In the illustrative example given above, the bottom of the cylinder block 20 is 2% vinches from the crankshaft center line and the bottom'of thepcylinder block 20b is 3% inches from the crankshaft centerline. While it is necessary to move the pistons 36b relatively away from the 'axis of the crankshaft the exactamount of the movement is not critical.

Actual tests have demonstratedconclusively--that-despite the asymmetrical arrangement of the engine it operates smoothly and with full efficiency. In facttests have demonstrated that the horsepower of the engine of Figure 2 exceeds the combined horsepower of two of the engines shown in Figure 1 by approximately l() percent.

This result is due to the relatively reduced friction losses brought about from the use, in the engine of Figure 2, of a single crankshaft, one set of main bearings and one set of connecting rod bearings. Inthe latter respect the engine of Figure 2 has a significant advantage over the usual opposed cylinder engine in which separate sets of connecting rod bearings are used. Also the weight of the engine of Figure 2 is considerably less than twice the weight of the engine of Figure 1 so that the engine of Figure 2 has a substantially better power weight ratio than the engine of Figure 1.

Since the particular engine shown is of the overhead cam design, the drive or tower shafts 62 for the cams of engine B are somewhat longer than the shafts 64 designed for the original engine 20. Apart from the substitution of longer tower shafts and an asymmetrical tower casting 66, no other modification in the valve actuating mechanism need be made.

The original carburetion system and intake manifold system may be retained if desired with appropriate linkage to permit simultaneous control of the carburetors. Preferably the original exhaust manifolds of'the individual engines are retained in the convertedengine of Figure 2. The manifolds may be positioned either above `or below the crankshaft center line.

The conventional ignition system for the four-cylinder engine of Figure 2 may be replaced by an ignition system suitable for an eight-cylinder engine or the original distributors 68, coils 'l0 and harness 72 may be used in the eight-cylinder engine.

In either case the distributors are timed so that each cylinder in one block iires simultaneously with a cylinder in the other block.

The firing order of the cylinders of one block is retained. The firing sequence of the cylinders of the other block is retained but the firing order is shifted to avoid ring directly opposite cylinders simultaneously. In a specific case the firing order of engine A may be 1, 3,-4, 2. The opposite bank has a tiring order of 3, 4, 2,'1. However, other arrangements may be'used, if desired.

No other significant changes, additions or modifications are required to complete the conversion.

lThe invention may be embodied in other specific forms without departing from thespiritor essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within-the meaning and range of equivalency of the claims-are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is: t

1. A method of converting an internal combustion engine having one `or more cylindersto an engine having twice as many cylinders, said engine having atsplit crankcase supporting a crankshaft and having pistons in said cylinders and capped connecting rods connecting said pistons and said crankshaft, comprising the steps of replacing the lower half of said split 'crankcase with'an adapter section, replacing the caps of said connecting rods with cap `assemblies each adapted to support an additional connecting rod, installing `said additional connecting rods on said cap assemblies, 'connecting saidA additional connecting rods to additional pistons, 'and assembling a cylinder block to said crankcase adapter section in a manner to dispose the cylindersof said cylinder block in alignment with the cylinders of said engine.

2. A method of converting an `internal combustion engine having one or more Vcylinders `to an -enginehav-y ing twice as many cylinders, said engine having a split crankcase supporting a crankshaft and having pistons in said cylinders and capped connecting rods connecting said pistons and said crankshaft, comprising the steps of replacing the lower half of said split crankcase with an adapter section, said adapter section being of greater depth than the upper half of said crankcase, replacing the caps Iof said connecting rods with cap assemblies each adapted to support an additional connecting rod, installing said additional connecting rods on said cap assemblies, connecting said additional connecting rods to additional pistons, assembling a cylinder block to said crankcase adapter section in manner to dispose the cylinders of said cylinder block in alignment with the cylinders of said engine and further from the center of crankshaft than the original cylinder block suiciently so the angularity 15 2734258 of the additional connecting rods is low enough to effect smooth and eicient operation of the engine.

References Cited in the le of this patent UNITED STATES PATENTS 1,208,854 Stitt Dec. 19, 1916 1,329,389 Field Feb. 3, 1920 1,811,625 Greening et al June 23, 1931 1,889,583 Woolson Nov. 29, 1932 2,218,332 Fowler Oct. 15, 1940 2,268,543 Coberly Jan. 6, 1942 2,452,232 Fischer Oct. 26, 1948 2,671,436 Pitt et al. Mar. 9, 1954 Shultz Feb. 14, 1956 

